1 files changed, 5 insertions, 1 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6d4569e0924d..36f260864f65 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4474,6 +4474,7 @@ static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
 void sched_show_task(struct task_struct *p)
 {
         unsigned long free = 0;
+        int ppid;
         unsigned state;
 
         state = p->state ? __ffs(p->state) + 1 : 0;
@@ -4493,8 +4494,11 @@ void sched_show_task(struct task_struct *p)
 #ifdef CONFIG_DEBUG_STACK_USAGE
         free = stack_not_used(p);
 #endif
+        rcu_read_lock();
+        ppid = task_pid_nr(rcu_dereference(p->real_parent));
+        rcu_read_unlock();
         printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
-                task_pid_nr(p), task_pid_nr(rcu_dereference(p->real_parent)),
+                task_pid_nr(p), ppid,
                 (unsigned long)task_thread_info(p)->flags);
 
         show_stack(p, NULL);